.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    font-family: "Helvetica Neue", Arial, sans-serif;
}

h1 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 30px;
}

.top-links p {
    text-align: center;
    font-size: 1.1rem;
    color: #333;
    margin-bottom: 30px;
}


.link-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
}

.link-card {
    display: block;
    flex: 1 1 250px;
    min-width: 200px;
    max-width: 300px;
    background-color: #f8f9fa;
    border: 1px solid #ccc;
    border-radius: 8px;
    padding: 20px;
    text-align: center;
    transition: background-color 0.3s ease;
    text-decoration: none;
    /* a要素全体がリンクでも下線を消す */
    color: inherit;
}

.link-card:hover {
    background-color: #e9ecef;
}

.card-link {
    font-size: 1.1rem;
    font-weight: bold;
}

.card-link:hover {
    text-decoration: underline;
}

@media (max-width: 600px) {
    h1 {
        font-size: 1.6rem;
    }

    .link-card {
        flex: 1 1 100%;
    }
}

.twitter-timeline-container {
    margin-top: 2em;
    border: 1px solid #ccc;
    border-radius: 8px;
    padding: 1em;
    background-color: #f9f9f9;
}

.race-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    font-size: 14px;
}

.race-table th,
.race-table td {
    border: 1px solid #ccc;
    padding: 6px 10px;
    text-align: center;
}

.race-table th {
    background-color: #f2f2f2;
}

.race-list h2 {
    margin-top: 40px;
}